Defend/AFK mode = space bar (make sure you're in group mode before you press it)
1-20 - AQM [waypoint]
21-40 - Tetra Ruins/Catacombs/Golden Road [waypoint] (in that order) Jezebel Glen for AFKing in your 30s
41-50 - Porto Bello Deck/Hold/Cabin [waypoint] (in that order)
51-60 - El Lago/Torche's Mansion [waypoint]
You'll become more knowledgeable about leveling places after 60~
Also, it's important that you check this
thread. Polish equipment are a necessity to AFK efficiently.